Dam.



PATENTED SEPT. 19, 19.05.

W. L. CHURCH.

DAM

APPLIOATION FILED JUNI.' 2. 1905.

INDREW, U GRINAM C0. PHON].UTMDGRAPNERSA WASHINBTON. D. CV

Nro. 799,929.

VILLIAM L. CHURCH, OF NEW'ION, MASSACHUSETTS.

DANI.

Specification of Letters Patent.

Patented Sept. 19, 1905.

Applatiou filed June 2, 1905. Serial No. 263,448.

To all Loh/07% t may concern:

Be it known that I, W'ILLIAM L. CHURCH, of Newton, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Dams, of which the following is a specilication.

This invention has especial reference -to dams for reservoirs of Waterworks where the quantity of overflow water is relatively small, although it may be embodied in other dams, if desired.

rhe invention has for its object to prevent the wearing away or scouring of the streambed at the downstream side of the dam by the impact of the overflowing water; and it consists in the improvements whichv I will now proceed to describe and claim.

The accompanying drawing represents a perspective sectional view of a dam embodying my invention.

In the drawing, 12 represents the deck of the dam, which is preferably inclined from its heel 13 to its crest 14, so that the crest over- {lianfgs the deck and the deck overhangs the 15 represents a wear-resisting bed extending downstream from the heel of the dam, the width of the bed or its extension downstream from the deck being such that all the overlow which passes over the crest of the dam falls upon the bed.

16 represents a baffle-wall which is located at the downstream side of the deck and is separated therefrom by a passage for overflow water, the said baflie-wall having a crest 17, which is preferably substantially flush with the crest of the deck and is separated from the latter by an opening containing transverse bars 18, forming a grid to prevent passage of logs, floating masses of ice, Sac., between the deck and the baie-wall. The opening between the baffle-wall and the deck is of suiiicient width to accommodate all the overliow which normally passes over the crest of the deck. rI`he baffle-wall is arranged to deiiect the said overflow backwardly to ward the deck for two purposes-irst, to reduce the force of the impact of the overflow water on the bed, and, secondly, to cause the stream to impinge upon the portion of the bed adjacent to the deck. The bed is thus enabled to sustain the wear caused by the impact of the overflow against it, and at the same time its width or extension downstream from the heel of the deck is enabled to be reduced to the minimum.

-I have here shown the parts'above described, excepting the bars 18, as composed of concrete reinforcedby metal rods 20. Similarlyconstructed buttresses 21 are provided at suitable intervals, the buttresses rising from the bed 15 and supporting the deck and the bafflewa l.

22 represents a beam of reinforced concrete which extends between the buttresses.

In case of a maximum overflow which cannot be accommodated by the passage between the deck and the baie-wall the surplus water passes over the crest 17 of the baliie-wall and impinges on the lower or downstream portion of the bed. The stream of surplus water is, however, cushioned by the stream deflected backwardly by the baiiie wall, so that the surplus water and any floating objects carried by it are not liable to injure the portion of the bed on which they impinge.

23 represents a barrier which may extend between the buttresses to form a pool adapted to confine a body of water under the baewall.

It will be seen that the described construction insures the substantially horizontal How ofthe overiow water upon the unprotected bed of the stream below the wear-resisting bed 15, so that liability of the scouring and washing of the unprotected portion of the bed is prevented.

I claim- 1. A dam having means at the downstreamY side of its crest for deiecting overiow water backwardly.

2. A dam having means at the downstream side of its crest for detlecting overilow water backwardly, and a Wear resisting bed arranged to sustain the impact of the deflected overiow water. l

3. A dam comprising a deck, a wear-resisting bed extending downstream from the heel of the deck, and a halide-wall located at the downstream side of the deck and adapted to direct overflow water backwardly toward the deck and upon the bed.

4. A dam comprising a deck, a wear-resisting bedV extending downstream from the heel of the deck, buttresses between ther bed and deck, and a baffle-wall supported by the buttresses at the downstream side of the deck and adapted to direct overow water backwardly toward the deck and upon the bed.

5. A dam comprising a deck, a wear-resisting bed extending downstream from the heel IOO IIO

of the deck, and a balfle-wall located at the downstream side of the deck and separated from the latter by an overflow-passage.

6. A dam comprising a deck, a wear-resisting bed extending downstream from the heel of the deck, a baille-wall located at the downstream side of the deck and separated from the latter by an overflow-passage, and a grid or grating in the upper portion of said passage.

7. A dam comprising' a deck, a wear-resisting bed extending downstream from the heel of the deck, a baliie-wall located at the downstream side of the deck and adapted to direct overiiow water backwardly toward the deck and upon the bed, the crest of the baffle-Wall being substantially iush with the crest ofthe deck and located over the bed.

8. Adam having an upstream crest, a down- G. F. BROWN, E. BATCHELDER. 

